EVOLUTION and ECOLOGY

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EVOLUTION and ECOLOGY
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BIODIVERSITY
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Climate zones determine communities
Figure 5-2
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Terrestrial biomes
Figure 5-9
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Ecological niche

• An organisms role in its community
• Includes
• what it needs to survive
• Nutrients
• Light
• Space (habitat)
• Oxygen or carbon dioxide
• Inorganic compounds
• How it interacts with other species
• The more available niches there are to fill, the
  greater the amount of organisms

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Niche diversification in African Rift Lake
Cichlids
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Model of Cichlid Fish Diversification
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Other examples of ecology influencing evolution

• Coevolution two species evolve in response to
  each other over time
• Pollinators and flowering plants
• Hosts and parasites
• Predators and prey
• Symbioses
• Competition

Hammer orchid
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Predation drives evolution of both predators and
prey

• Predators adaptations
• Locate, sneak up on subdue prey
• Prey adaptations
• elude defend

horns, speed, coloration
spines, thorns, toxins
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Symbiotic interactions

• parasitism (-/)
• mutualism (/)
• lichens (algae fungus)
• commensalism (/0)
• barnacles attached to whale

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Competition can affect niches
High tide
Species 1
Low tide
Chthamalus sp.
Species 2
Fundamental niches
Realized niches
Semibalanus sp.
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Ecosystems
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Two Necessities for Survival Energy Flow and
Matter Recycling
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Producers Basic Source of All Food

• Most producers (autotrophs) capture sunlight to
  produce carbohydrates by photosynthesis

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Consumers Eating and Recycling to Survive

• Consumers get their food by eating or breaking
  down all or parts of other organisms or their
  remains.
• Herbivores (primary consumers)
• Carnivores
• Omnivores

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Respiration Getting Energy for Survival

• Organisms break down carbohydrates and other
  organic compounds in their cells to obtain the
  energy for internal reactions.
• This is done through aerobic respiration or
  anaerobic respiration.

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Decomposers and Detrivores
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Energy Flow

• Energy flows through an ecosystem
• Route of energy flow is determined by an
  ecosystems trophic structure.
• Trophic interactions move energy through an
  ecosystem

Simple example
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Humans can impact natural food webs

• Chemical pollutants
• Invasive species
• Overhunting

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Energy Flow in an Ecosystem Losing Useful Energy
in Food Chains and Webs
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MATTER CYCLING IN ECOSYSTEMS

• All organisms are made up of organic molecules
• Carbohydrates
• Proteins
• Lipids
• Nucleic acids
• Essential nutrients are those that are required
  to make the organic molecules
• C, H, N, O, P, S
• Organic matter cycles within ecosystems
  (biogeochemical cycles)
• Both autotrophs and decomposers play vital roles

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Carbon Cycle
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The Nitrogen Cycle Bacteria in Action
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Phosphorus cycle